This work involves the design, testing and use of radionuclide generators to produce alpha-emitters to be attached to proteins for use in radiotherapy. A new radionuclide generator has replaced the previous design which used Th-228 as the parent. The long half-life, two years, made it unsuitable for use by personnel without training in the handling of long-lived activity. We have undertaken a project with the Chemistry Division at Argonne National Laboratory to develop a new generator system based on the parent Ra-224. This radionuclide has a 3.5 day half-life reducing the potential problems associated with a longer lived radionuclide. We designed and tested a separation system to separate thorium and radium in a manipulator-equipped shielded cave. We have had this system in operation for one year. Simultaneously, we developed a new generator which will use the radium parent. This system uses a disposable generator package to minimize shipping and handling. An organic cation exchanger is eluted with hydrochloric acid to yield either the bismuth daughter or lead daughter. Work with this system has shown that the generator is safe, has good operating characteristics and can be produced on a regular basis.